1. Asymmetrical digital subscriber line (ADSL) transceivers—ITU-T G.992.1 July 1999
2. ITU-T‘Single-Pair High-speed Digital Subscriber Line (SHDSL) Transceivers’, Recommendation G.991.2, 2001
3. Asymmetrical Digital Subscriber Line (ADSL) transceivers—Extended bandwidth ADSL2 (ADSL2+) Annex J—ITU-T G.992.5 ADSL2 standard May 2003